Most visitors descended 3,067m slopes but scores were trapped due to poor visibility and toxic gases. Most of people were rescued. More than 60 people needed medical care and more than 40, suffering from serious injuries, were taken to hospital.

Rescuers suspended operations there on Monday because of toxic gases and the threat of lava discharges. Reports that people were found alive have not been confirmed.

Thirty-two people were discovered on the volcano with lung and heart failure, police said. The bodies of 12 of them were carried down by helicopter.

Ontake last erupted in 2007. In a powerful eruption in 1979, the giant released more than 200,000 tons of ash.